Method of forming a notched edge lock screw

#In stamping presses which are used for blanking, drawing, punching and piercing relatively small sheet metal objects, it is conventional to fasten the dies within retainer plates or rings which, in turn, are fastened to the press platens and the like movable parts. Such dies, including punching and forming dies, are removable from the retaining rings or plates for replacement when desired.

#Examples of such type of presses and retainers within which die parts are fastened are illustrated in U.S. Pat. No. 2,089,795 issued Aug. 10, 1937 to Hodge, U.S. Pat. No. 2,699,830 issued Jan. 18, 1955 to Hodge and U.S. Pat. No. 3,213,799 issued Oct. 26, 1965 to Koch. The press illustrated in the Koch patent is of a horizontally movable type which is particularly useful for accurately stamping small sheet metal parts from larger sheets.

#In the conventional presses, the retainer rings or plates, normally comprise a relatively thick metal plate which may be circular or polygonal in shape, having a socket which usually is circular. The die is provided with a part which fits within the socket where it is locked during stamping use. The locking mechanism which is conventionally utilized is in the form of a lock screw.

#FIG. 1 is a front view of a die retainer ring within which is mounted a die.

#FIG. 2 is a cross-sectional view taken in the direction of arrows 2--2 of FIG. 1.

#FIG. 3 is a perspective view of the retainer ring with the die removed.

#Referring to FIG. 1-3, the die retainer ring 10 is shown in a circular or annular form. Conventionally such retainers are either ring shaped or polygonal in shape, such as square. Thus, the ring formation is illustrative for purposes of this application.

#A back-up plate 11 is secured to the ring by means of screws 12 extending through openings 13 formed in the ring (see FIGS. 1 and 3). The plate is provided with a central hole 14 for the passage of knock-out pieces in punching operation. The central opening in the ring forms a socket 15.

#A die part 16 fits within the socket 15. The die part may be either a complete die or punch or a compound die or punch of a known type. Thus, it is illustrated generally schematically and as representative of conventional die parts. The die is provided with a forming end 17 which may be used for punching or blanking or drawing or the like, along with the mating die parts of an upper die or opposing die, which is not illustrated herein.